GSpeed C7 Z06 Corvette Cooling System Testing Part III
For Saturday's test runs, we laid the auxiliary radiator down horizontally in front of the main radiator.
In this picture, you can see the radiator laying down, along with the super-high-tech cardboard vanes.
Here's a schematic of how we routed everything:
First session of the day was at 10:30 on Saturday morning. We weren't able to get the second air temp sensor wired up in time, so we don't have temperatures off the back of the auxiliary radiator, but here's what we saw for water temps:
Our intercooler fluid gremlin is still present, but otherwise the blower coolant temps seem to be happy around 120°F.
Airflow temps are looking good, you can see ambient temps were about 90°F at the time.
Water temperature differential shows a pretty even split.
Since we only had two air temp sensors on Saturday, we didn't get air temp differential across the aux radiator, but the main radiator is looking pretty strong, with over 100°F air temp change.
Here are the stats we got off the PDR:
Laps Completed: 6
Best Laptime: 1:21.8
Max Water Temp: 232°F
Max Oil Temp: 302°F
Max Trans Temp: 237°F
So water temperatures are now looking pretty good. There's a slight discrepancy between the PDR numbers and our Aim datalogger's numbers, which we'll be looking into further. Oil temperatures, though, are pretty concerning. So for the next session, we rigged up a second oil cooler in the front bumper just inboard of the left brake duct.
Here's the temperatures we saw:
You can see the air temps are much higher (100°F ambient) so everything is pretty thoroughly heat soaked.
What's somewhat interesting is that as the ambient temperatures climb, the main radiator begins to bear more of the load. The intercooler is still pulling plenty of heat out of the blower, and the engine is pretty happy, overall.
From the PDR:
Laps Completed: 12
Best Laptime: 1:22.4
Max Water Temp: 237°F
Max Oil Temp: 302°F
Max Trans Temp: 275°F
We ran 12 laps at an aggressive pace in 100°+ weather, which is a massive improvement over stock. Water temps of 235°ish aren't great, but we'll accept it enough to focus on other problems. Like trans and oil temps. We're a little surprised our extra oil cooler didn't help anything, so we're going to revisit that this week as well. The trans cooler is underneath the auxiliary radiator, so it's no surprise it's not doing much good under there when everything gets hot.
At the end of the day, we put Operations in the car (our test driver had been at the wheel for previous tests) to log some data and enjoy the car.
Overall, things are pretty happy for a supercharged car running in 100° weather. Engine coolant temps reach a pretty happy equilibrium at around 220°.
Temperature gradients look pretty similar to what we saw earlier in the day.
PDR Data:
Laps Completed: 6
Best Laptime: 1:23.8
Max Water Temp: 230°F
Max Oil Temp: 297°F
Max Trans Temp: 275°F
It's pretty clear transmission temps build up at anything over 6-8 laps. That's our next hurdle, getting trans and oil temps back down to reasonable/survivable track car levels.
In this picture, you can see the radiator laying down, along with the super-high-tech cardboard vanes.
Here's a schematic of how we routed everything:
First session of the day was at 10:30 on Saturday morning. We weren't able to get the second air temp sensor wired up in time, so we don't have temperatures off the back of the auxiliary radiator, but here's what we saw for water temps:
Our intercooler fluid gremlin is still present, but otherwise the blower coolant temps seem to be happy around 120°F.
Airflow temps are looking good, you can see ambient temps were about 90°F at the time.
Water temperature differential shows a pretty even split.
Since we only had two air temp sensors on Saturday, we didn't get air temp differential across the aux radiator, but the main radiator is looking pretty strong, with over 100°F air temp change.
Here are the stats we got off the PDR:
Laps Completed: 6
Best Laptime: 1:21.8
Max Water Temp: 232°F
Max Oil Temp: 302°F
Max Trans Temp: 237°F
So water temperatures are now looking pretty good. There's a slight discrepancy between the PDR numbers and our Aim datalogger's numbers, which we'll be looking into further. Oil temperatures, though, are pretty concerning. So for the next session, we rigged up a second oil cooler in the front bumper just inboard of the left brake duct.
Here's the temperatures we saw:
You can see the air temps are much higher (100°F ambient) so everything is pretty thoroughly heat soaked.
What's somewhat interesting is that as the ambient temperatures climb, the main radiator begins to bear more of the load. The intercooler is still pulling plenty of heat out of the blower, and the engine is pretty happy, overall.
From the PDR:
Laps Completed: 12
Best Laptime: 1:22.4
Max Water Temp: 237°F
Max Oil Temp: 302°F
Max Trans Temp: 275°F
We ran 12 laps at an aggressive pace in 100°+ weather, which is a massive improvement over stock. Water temps of 235°ish aren't great, but we'll accept it enough to focus on other problems. Like trans and oil temps. We're a little surprised our extra oil cooler didn't help anything, so we're going to revisit that this week as well. The trans cooler is underneath the auxiliary radiator, so it's no surprise it's not doing much good under there when everything gets hot.
At the end of the day, we put Operations in the car (our test driver had been at the wheel for previous tests) to log some data and enjoy the car.
Overall, things are pretty happy for a supercharged car running in 100° weather. Engine coolant temps reach a pretty happy equilibrium at around 220°.
Temperature gradients look pretty similar to what we saw earlier in the day.
PDR Data:
Laps Completed: 6
Best Laptime: 1:23.8
Max Water Temp: 230°F
Max Oil Temp: 297°F
Max Trans Temp: 275°F
It's pretty clear transmission temps build up at anything over 6-8 laps. That's our next hurdle, getting trans and oil temps back down to reasonable/survivable track car levels.